# UNDERSTANDING MOISTURE DAMAGE

How does humidity cause moisture damage?

The relative humidity $\left(\phi\right)$ of an air-water mixture is defined as the ratio of the partial pressure of water vapor (H2O) $\left({e_w}\right)$ in the mixture to the saturated vapor pressure of water $\left({{e^*}_w}\right)$ at a given temperature.

Relative humidity is normally expressed as a percentage and is calculated by using the following equation:

$\phi = {{e_w} \over {{e^*}_w}} \times 100\%$ RH (Relative Humidity) is the quantified unit used to describe the level of humidity.

Different types of moisture damages occurs at different humidity levels. The average relative humidity level can be found by looking to the local weather reports in your area. Maintenance of most objects below 50% RH at room temperature can protect items from moisture caused damages.

The Relationship Between Mold Growth, Temperature, and Relative Humidity
Mold grows and proliferates at a temperature range of 12~38°C when humidity is greater than 60%.

What is condensation?
Condensation is water vapor suspended in the air settling on cool surfaces.

• By washing, cooking and breathing, the average family creates up to 20 pints (11.36 Liters) of moisture every day. This moisture must go somewhere and be dealt with to avoid condensation. However, condensation could appear in many forms and the most common being steaming windows. And in extreme cases, dark spots of mold will appear. Condensation is the result of a build up of moisture caused by our normal lifestyle and it's unavoidable.
• Photography, cinematography, and other equipment collects moisture while in the field. Temperature changes is inevitable when those equipment are stored and transported to a cooler/warmer environment causing condensation ro frosting to occur. In the long term, damages will occur to these pricey investment.
• In SMT manufacturing process, solder must be stored at low temperature environments of 2°-6° Celsius. Prior to use, the solder must be brought to ambient room temperatures, of which will cause condensation to occur. If this condensation is present during the reflow process, it will cause a decrease in production yields.
• After PCB and/or MSD materials utilizes high temperature baking to remove moisture and is placed in ambient room temperature, condensation will collect and penetrate in sensitive areas.

Eureka Auto Dry Box's Solution To Moisture Damages

• Eureka Auto Dry Box Series (25%~55% RH) provides the best moisture damage prevention for aging, molding, spoiling, rusting, corrosion, denaturing, etc.
• Eureka Fast Super Dryer Series (<20% RH, <10% RH, <5% RH) provides the best solution for trace-moisture damages in manufacturing components/materials, integrated circuitry, MSDs, etc.

Moisture Damages Caused By Ambient Humidity

• Objects begins to mold and spoil at 60% RH.
• Objects begins to deteriorate, age, and oxidize at 35% RH.
• Precious resources and materials suffers denaturing caused by trace moisture at 20%RH.
• IPC/JEDEC J-STD-033B standard indicates that MSD (Moisture-Sensitive Devices) stored properly at <10%RH or <5%RH will elongate floor life.

Manufacturing materials, precision parts, components and other resources can be protected from oxidation by maintaining storage environment at or below 35% RH
Clearly, Eureka Auto Dry Boxes / Fast Super Dryers are essential appliances and instruments in your living and work environments. So, are you protecting the investment in your life and conserving resources for the future?  today for solution with any moisture control problems, product and pricing inquiries, or on how to join our dealer/distributor program.